Choosing the right fire alarm isn’t simply a case of installing the same detector in every room. Different environments present different fire risks, and the type and location of your detectors can affect how quickly a fire is identified.
A busy commercial kitchen, for example, needs a different form of detection from an office, warehouse or escape corridor. Larger and more complex premises may also require a more sophisticated fire alarm system capable of identifying exactly where an alarm has been triggered.
For businesses, the appropriate level of fire alarm protection should be determined by the risks within the building. A professional fire risk assessment can identify those risks and help establish the fire safety measures your premises require.
What Are the Different Types of Fire Alarm Detectors?
Several types of detector can form part of a fire alarm system. Each responds to fire in a different way, making some better suited to particular environments than others.
Optical Smoke Detectors
Optical smoke detectors use a light sensor to identify smoke entering the detector chamber. They are particularly effective at detecting the larger smoke particles associated with slow, smouldering fires.
These detectors are commonly suitable for areas such as offices, corridors, reception areas and other general occupied spaces.
However, smoke detectors need to be positioned carefully around environments that regularly produce steam, fumes or airborne particles, as these can contribute to unwanted alarms.
Heat Detectors
Rather than looking for smoke, heat detectors respond to changes in temperature. This makes them useful in environments where smoke or steam could regularly trigger a conventional smoke detector.
They are commonly installed in commercial kitchens, garages, workshops and other areas where heat, fumes, dust or steam may be present.
Because heat detectors generally need a fire to develop sufficiently to produce an increase in temperature, they are not simply interchangeable with smoke detectors. Their suitability depends on the individual risk and the wider fire alarm design.
Multi-Sensor Detectors
Multi-sensor detectors use more than one method of identifying a potential fire, such as combining optical smoke detection with heat sensing.
By assessing multiple signs of fire, these detectors can provide reliable detection while helping to reduce unwanted alarms in suitable environments.
They can be used across many commercial settings, including offices, accommodation, communal areas and other spaces where different types of fire could potentially develop.
Manual Call Points
Manual call points allow someone who discovers a fire to raise the alarm immediately. They form an important part of many commercial fire alarm systems and are usually positioned in accessible locations along escape routes and near exits.
Their exact positioning should form part of the overall fire alarm system design so that occupants can raise the alarm quickly while evacuating the premises.
Conventional, Addressable and Wireless Fire Alarm Systems
The detectors themselves are only one part of a commercial fire alarm system. Businesses may also need to choose between different types of system depending on the size, layout and use of their premises.
Conventional Fire Alarms Systems
Conventional systems divide a building into different detection zones. When an alarm activates, the control panel identifies the zone in which the activation has occurred rather than the individual detector.
They can provide a straightforward and cost-effective solution for smaller or less complex commercial premises where identifying the affected area by zone provides sufficient information.
Addressable Fire Alarm Systems
With an addressable system, individual devices have their own electronic address. The control panel can therefore identify the particular detector or call point that has been activated.
This makes addressable systems especially useful for larger buildings, multi-storey premises and more complex sites, where knowing the precise location of a potential fire can help staff and emergency responders react more quickly.
Wireless Fire Alarm Systems
Wireless or radio fire alarm systems communicate without requiring the same extensive cabling as traditional wired systems.
They can be particularly useful in listed or historic buildings, occupied premises where disruption needs to be minimised, or buildings where installing new cabling would be difficult.
Wireless doesn’t mean that the system can simply be positioned anywhere, however. It still requires proper design, installation, commissioning and ongoing maintenance.
What Do Fire Alarm Categories Mean?
You may encounter terms such as L1, L2, L3, L4, L5, M, P1 and P2 when researching commercial fire alarm systems.
These aren’t different detector technologies. Instead, BS 5839-1 uses categories to describe the purpose and extent of fire detection provided within a non-domestic building.
Category M is based on manual activation, while the L categories are concerned with protecting life. L1 provides the most extensive automatic detection coverage, while L2 to L5 provide different levels or forms of life protection according to the risks within the premises. P1 and P2 systems focus primarily on protecting property, with P1 providing wider coverage and P2 concentrating on defined parts of a building.
There isn’t one category that is automatically right for every business. The appropriate fire alarm category should be based on the building, its occupants, fire risks and the findings of a fire risk assessment.
Where Should Fire Alarms Be Installed?
Correct positioning is just as important as choosing the right type of detector.
Smoke detectors are generally suited to circulation spaces and occupied rooms where early smoke detection is needed, while heat detection is often more appropriate in kitchens or environments where smoke, dust or steam could create false alarms. Manual call points need to be accessible to people leaving the building, while the overall level of automatic detection will depend on the required fire alarm category.
Factors such as ceiling height, walls, ventilation, room layout, escape routes and the activities taking place inside each area can all influence the final design.
For that reason, commercial fire alarms should be designed around the individual premises rather than installed according to a one-size-fits-all layout.
Maintaining the Right Fire Alarm System
Choosing and installing an appropriate system is only the beginning. Fire alarms must also remain operational throughout their service life.
Regular fire alarm maintenance can identify issues with detectors, batteries, call points, sounders and control equipment before they compromise the performance of the system.
Black & Gold Fire Safety is BAFE SP203-1 registered for fire alarm design, installation, commissioning and maintenance, with more than 20 years of experience working with businesses, schools and organisations.
If you’re unsure which type of fire alarm your premises requires, whether your existing system provides adequate coverage or whether your alarms are due a service, contact Black & Gold Fire Safety for expert advice and a no-obligation conversation.
